‘UNITIZED’ BONDED PTFE LIP SHAFT SEALS
Paul
Components offers bonded PTFE lip Seals providing a Sealing
System by unitizing a bonded PTFE wafer type Sealing lip
with steel wear sleeve. This unique version is capable of
handling contamination and oil degradation effects over
longer period of time. This Unitized Seal has many advantages
over assembled *PTFE lip Seals and flouroelastomer lip Seals
due to mainly following reasons: -
- PTFE material is bonded to rubber elastomer.
- Bonder rubber OD or sealant coated metal OD.
- Sealant Coated Inner Steel Ring.
- Axial Sealing lip for excluding dirt.
- Unitized Construction.
- Suitable for Crankshaft Sealing application experiencing
excessive temperature & speed
| DESIGN
COMPARISON OF UNITIZED & NON UNITIZED PTFE SEALS. |
| Design
Variable |
Non
Unitized
(Assembled PTFE Seal) |
Unitized
(Bonded PTFE Seal) |
| PTFE
wafer support |
Two
PTFE wafers are mechanically held between and inner and
outer cup with an ‘O’ Ring asbestos gasket
preventing leakage internally between the cups. Incorrect
assembly or flaws in any of the components could result
in internal leakage. |
One
PTFE wafer is bonded to the rubber, which also provide
a beaded outer diameter. All potential internal leak paths
are eliminated when the components are bonded together
during molding. |
| Dirt
exclusion lip |
A
separate radial PTFE wafer, providing only a barrier to
external contaminates. |
As
axial, rather than a radial dirt lip, lengthens the distance
between the primary lip and the dirt lip, giving a longer
leak path. Rotation of the sleeve flange provides a slinger
action radially outward, away from the oil-sealing surface. |
| O.D.
Sealant |
Metal
O.D. with layer of O.D. sealant offers some protection
against static leakage due to minor bore imperfection
or damage. |
Beaded
rubber O.D. offers maximum sealability to bore imperfections,
axial scratches, rough finishes high oversize bores, aluminum
retainers, etc. |
| Number
of components |
-
Outer metal L-Cup
- ‘O’
Ring/Gasket
-
Oil Sealing PTFE wafer
-
Dirt lip exclusion PTFE wafer
-
Inner metal L-Cup
-
Outside diameter sealant
|
-
Seal metal L-Cup
-
Rubber
-
Dirt and oil sealing lip PTFE wafer
-
Wear Sleeve
|
CONCLUSION:
The
unitized bonded PTFE Seal offers several design advantages
over the assembled PTFE, laminated PTFE, and flouroelastomer
Seals:
- Improves
on contaminant exclusion with an axial slinger lip.
-
Reduces the number of components required for the assembled
design, which in turn eliminates the potential leak path.
-
Combines the Seal and sleeve into one package (unitized),
eliminating possible damage to the PTFE wafer during handling
or installation (unitized implies a single package in which
the major elements cannot be separated).
-
Provides a rubber O.D. to eliminate O.D. leakage in poorly
manufactured housing bores.
PTFE
Seals in comparison with flouroelastomer lip Seals offer advantage
of low under lip temperature, good hot and ultra low temperature
lip followability.
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|
